Suction cleaner filter



NOV. 27, D, c, GERBER SUCTION CLEANER FILTER Filed Sept. 3, 1947 Fly. 1

INVENTOR. De la C. Gerber f a ATTORNEY.

Patented Nov. 27, 1951 SUCTION CLEANER FILTER Dale G. Gerber,.NorthCanton, Ohio, assignor to The Hoover Company, NorthCanton, Ohio, a

corporation of Ohio Application September 3, 1947, Serial No. 771,967

The present invention relates to filters and more particularly tofilters composed of fibrous material having exterior fibers removed.

In the usual filter for suction cleaners the material has a mattednapped surface to which the dirt adheres and prevents removal of thedirt when the filter is cleaned,- and as a result when the filter isre-used the back pressure becomes excessive and reduces the cleaning-efficiencyofthe suction cleaner. The present invention provides afilter fabric wherein the matted napped. surface'is' removed to form asmooth surface upon which the dirt initially contacts, and the smoothsurface functions ,to cause the easy removal of the dirt depositedthereon when the filter is cleaned. Removal of the matted napped surfacedoes not injure the fibers in the body portion of the filter materialand thus the filtering efficiency of the material. is not reduced;

. An object of the invention is toprovide a filter forinedf from fibrousmaterial. Another object is to provide a fibrous filter havingprojecting fibers shortened while retaining the necessary filtering.characteristics. A further object is to provide a fibrous filter adaptedfor use with a suction cleaner and having the fibers in the dirtcontacting surface shortened to form a smooth dirt collecting surfacewhich can be easily cleaned. Another object is to provide a method ofshortening fibers projecting from the body of a fibrous filter material.Still another object is to provide a method of treating fibrousfiltering material by subjecting the material to an electrical charge toraise fibers from the body of the material and thereafter shortening thefibers by v singeing the latter to substantially the body of thematerial. Other objects and advantages of the invention will be apparentfrom the following specification and drawing, wherein:

Figure 1 illustrates the filter in a suction cleaner;

Figure 2 is a view of the apparatus for creating an electrical charge inthe filter material to raise the fibers and to singe the projectingfibers;

Figure 3 is a section of the filter material prior to shortening thefibers; and

Figure 4 is a section of the filter material after the fibers have beenshortened on the dirt contacting surface of the filter.

The invention herein disclosed is for purposes of illustration appliedto a suction cleaner comprising a casing l supported on runners II andhaving a suction end cap I2 and an exhaust end cap IS. The end cap I! isprovided with an inlet 3' Claims. (01. 183-5 1) 2 r M for connection toan unshown hose andcleaning tool which engages a surface to be cleaned,

and the rear end cap l3 has an outlet l5 which.

canalso-beprovided-with a cleaning toolina manner Well known in the art.Adirt filtering bag is is supported in the casing lfl to remove thedirt-from the dirt-laden airpassing through the inlet l4 into the bag,and a-motor-fan unit I] provides the suction for moving the air streamand exhausting it through the outlet l5. The

filter materialmay be paper; cloth or other suit,-

able material and as shown in Figure 3 prior ,to v being. processed is asingle ply cloth 21L having yarnsil vsecured together by warp face yarns22,

23, and 24. The exposed surfaces 30, and-3l of the material prior tobeing processed-is a mass of intermingled matted fibers or nap 32, andit is these fibers which retain the dirt in the usual suc-.

tion cleaner bag and prevent .removing all of the dirt when the bag isbeing cleaned.

The process for removing the matted fibers or nap 32 from the surface 30is shown in Figure 2 sides of the material, and the electrodes areconnected to a suitable source of high frequency current. Disposed abovethe electrode 40 and beneath the material 20 is a gas manifold 42 havingtwo rows of burners 43--43 in the electrostatic field and adjacent theouter fibers of the material.

Movement of the material between the electrodes 40 and 4| causes thematerial to pass through the electrostatic field and the fibers receivean electrical charge and are aligned with the electric field, and as aresult of such charge the nap or fibers are pulled away from and areperpendicular to the body of the material so that the fibers are nolonger matted into the body of the material. While the fibers are raisedfrom the body of the material, the burners 43-43 singe the ends of thefibers to shorten the latter andthus prevent the fibers from forming amatted surface, and the resulting surface shown at 45 in Figure 4provides a relatively smooth dirt contacting surface from which the dirtmay easily be removed when the filter is being cleaned.

The speed of movement of the material between the electrodes 40 and 4|depends upon the size of the electrodes, thestrength of theelectrostatic field and the heat of the singeing fiame.

I have found that the voltage applied to the electrodes can be variedover a wide range and have employed voltages from 1500 to 4000 persquare inch. If desired the burners 43 can be arranged to one side ofthe electrodes 40 and 4|.

The processed filter material shown in Figure 4 is formed into, the dirtfiltering bag IS with the smooth surface 45'forming the, interior-andthe napped surface 3| the exterior of the bag; The dirt-laden air passesthrough the inlet l4. into the bag l6 and first contacts the smoothinner surface 45, and the remaining portion of' the filter body removesthe dirt from the dirt-laden air stream as the latter passes through thematerial, and the cleaned air is then discharged through the outlet l5.

In cleaning the bag Hi, the end cap l4 and the bag I 6 are removed andthe dirt is easily dislodged from the bag because of the relativelysmooth inner surface 45.

While I have shown and'described' buta single modification ofmyinvention, it is to be understood that this modification is to betaken as illustrative only and not in alimiting sense. I

do not wish to be limited to'the particular'structure and process shownand described, but to include all equivalent variations thereof exceptas limited by the scope of the claims. *Iclaim:

In a suction cleaner. a dirt filtering bag having anopening-ior'emptyingcollected dirt, suction; creating means for moving an air stream fromthe interior'of said bag and through the walLthereof ;to remove the dirtin said air stream, said filter b'a'g being of fibrous material including in its structure relatively long fibers projecting from the bodyofthe material to form the exterior surface ofrsaid bag, said materialin-. cluding relatively short fibers projecting from the body of said,material to formthe inside surface of l the bag, said short fibersinitially con tacting .saidair streanrto remove dirttherefromL saidshort fibers providing a. relatively smooth.

surface interiorlyiof the bag for easily. dislodging' the collected dirtthrough said bag opening.

2. A dirt filter adapted for use in a suction cleaner having suctioncreating means for mov-.

ing an air stream'through a filter and comprising: ,a-fibrous materialincluding inits structure; relatively long fibers and relatively shortfibers.

projecting from opposite sides of the body of said material, said shortfibers on one side of said body being charred to present a relativelysmooth surface of short fibers so disposed in the cleaner to initiallycontact the dirt to be removed from the air stream and collecting someof the removed dirt thereon, said relatively long fibers on the oppositeside of saidbody beinguncharred to remove any dirt remaining in the airstream, the

charred short fibers forming said smooth surface initially contactingthe dirt permitting easy removal of dirt collected thereon to clean saidfilter in comparison to any dirt which may have collected on saidrelatively long uncharred fibers on said opposite side of said material.

' 3,.In a. suction cleaner, a dirt filtering bag having an opening foremptying collected dirt, suction;creatingrmeans for moving an air streamfrom the interior of said bag and through the wall "thereof to removethe dirt in said air stream, said filter bag being of fibrous materialincluding in its structure'fibers shortened to'substantiallythe bodyofthe material to form the interior surfaceof said bag to initiallycontact' thedirt, said shortened fibers so projecting from said'bodyof='the material to form an unmatted fibrous surface to provide arelatively smooth interior surface on said bag for easily dislodging"the collected dirt therefrom through said bag opening; I I

y l DALE C. GERBER;

' REFERENCES CITED 'The iollowing'references are of recordinthe file ofthis patent: i

' UNITED STATES PATENTS

